Analysis of repeatability of Diesel engine acceleration

The analysis of combustion non-repeatability in the dynamical working conditions of a Diesel engine is presented. In the frame of statistical analysis, applied to a number of acceleration trails, basic determinants such as standard square deviation, skewness, and kurtosis have been calculated for the mean indicated pressure (MIP). The methods of return maps, delay phase portrait reconstruction, recurrence plots and quantification recurrence analysis have been also used to analyze a single chosen course of the measured pressure starting from the idle run of engine, through its acceleration process and ending on a stable engine run with a certain velocity. The results show that recurrence techniques are able to identify various phases of the engine non-stationary work.     

Synaptic Alterations in a Transgenic Model of Tuberous Sclerosis Complex: Relevance to Autism Spectrum Disorders

Tuberous sclerosis complex (TSC) is a rare, multi-system genetic disease with serious neurological and mental symptoms, including autism. Mutations in the TSC1/TSC2 genes lead to the overactivation of mTOR signalling, which is also linked to nonsyndromic autism. Our aim was to analyse synaptic pathology in a transgenic model of TSC: two-month-old male B6;129S4-Tsc2^tm1Djk/J mice with Tsc2 haploinsufficiency. Significant brain-region-dependent alterations in the expression of several synaptic proteins were identified. The most prominent changes were observed in the immunoreactivity of presynaptic VAMP1/2 (ca. 50% increase) and phospho-synapsin-1 (Ser62/67) (ca. 80% increase). Transmission electron microscopy demonstrated serious ultrastructural abnormalities in synapses such as a blurred structure of synaptic density and a significantly increased number of synaptic vesicles. The impairment of synaptic mitochondrial ultrastructure was represented by excessive elongation, swelling, and blurred crista contours. Polyribosomes in the cytoplasm and swollen Golgi apparatus suggest possible impairment of protein metabolism. Moreover, the delamination of myelin and the presence of vacuolar structures in the cell nucleus were observed. We also report that Tsc2^+/− mice displayed increased brain weights and sizes. The behavioural analysis demonstrated the impairment of memory function, as established in the novel object recognition test. To summarise, our data indicate serious synaptic impairment in the brains of male Tsc2^+/− mice.     

Utilization of bog iron ores as sorbents of heavy metals

Sorption properties of bog iron ores with respect to Pb, Cu, Zn, Cr are evaluated at various pH. Maximum sorption determined in the experiments equals to 97.0, 25.2, 25.5, 55.0mg/g for lead(II), copper(II), zinc(II), and chromium(III), respectively. Chromium(VI) is bound in the amount of up to 10.0mg/g. The values of desorption indicate that most of the metals remain stably bound to the surface of bog iron ores, indicating that the chemisorption process prevails. The metals are sorbed as cations at the pH values from 4 to 9. Within this pH range up to 100% of the initial metal amount is immobilized. 90-100% of Cr(VI) is sorbed at pH between 3 and 5. Such properties, combined with favorable conditions of shallow mining and resultant low costs, may be regarded as an incentive for local utilization of bog iron ores in the environmental protection practice.     

Flexible multibody modeling of reeving systems including transverse vibrations

This paper presents a discretization procedure for the flexible multibody modeling of reeving systems. Reeving systems are assumed to include a set of rigid bodies connected by wire ropes using a set of sheaves and reels. The method is capable to model the deformation of the varying-length wire-rope spans. Wire ropes are assumed to deform axially, transversally and in torsion. This paper shows the capability of the presented method to model transverse vibrations. The discretization procedure uses a combination of absolute position coordinates, relative-transverse deformation coordinates and longitudinal material coordinates. Each wire-rope span is modeled using a single two-noded element under an arbitrary Lagrangian–Eulerian approach. The discretization method is validated using analytical and numerical reference solutions found in the literature that describe the dynamics of varying-length strings. In addition, the dynamics of a three-dimensional tower crane is simulated.     

A numerical analysis of heat and mass transfer processes in a macro-patterned methane/steam reforming reactor

The presented paper focuses on a numerical analysis of a heat and mass transfer process in a novel type of methane/steam reforming reactor. The novelty of the macro-patterned reactor design lies in dividing a reformer into segments of various lengths and reactivity. Precisely, splitting the catalyst and filling the created empty volume with porous, non-reactive, thermal conducting material such as metallic foam. This approach allows for moderating a sharp temperature drop at the inlet of the reactor typical for the endothermic methane/steam reforming process. To analyze the considered system, the mathematical and numerical models of transport phenomena and the reaction kinetics were developed and implemented into an in-house solver. The kinetics of methane/steam reforming was taken from the literature. The outlet composition obtained from the kinetic model was compared with the experimental measurements and good agreement was found. The conducted numerical analysis includes cases that differ from a number and lengths of catalytic and non-catalytic segments. The obtained results indicate that the macro-patterned design is a promising strategy that allows for a significant improvement of temperature distribution in a reforming reactor. It was shown that the proposed approach could help to cut the cost of the catalyst material by allowing for the conversion of methane with a smaller amount of the catalyst close to the reference case.     

Scalable Measurement System for Multiple Impedance Gas Sensors

Author proposes scalable architecture of the measurement system for gas sensor with impedance dependance of the gas concentration. The main part of the system is a single-board impedance analyser. The number of analysers working in parallel can be configured according to specific application. The system is controlled by a single computer which organises the measurement cycle and stores the acquired measurement data. The system is based on I2C-like interface and uses broadcast addressing to achieve parallel synchronisation and individual addressing to program individual setting and retrive the measurement data.